Feature/week7 mod1

I ran into two problem
1. in `spec/features/invite_friend_spec.rb:41`, if not add `sleep(2)`, the test will failed.
    in `environments/test.rb:17`, if use `localhost:52662`, the test will also failed.
2. in `payments.js`, disable submit is not working, it also send twice submit, then raise an exception from stripe.
I addressed this in the response on Tealeaf.  Your spec currently cannot fail though.  You forgot to create expectations (visit people, expect to see friend's name).  As I said in the response on Tealeaf though, you will need an expectation BEFORE you visit anything else, that will cause it to wait until the page finishes loading and your code has finished running.